I have bad knees so I cannot do any motion with impact, but I have find light weights, just moving around (ok, so some people have refered to it as flailing around, but never mind the haters) helps to lift the heart rate.

I think that by lifting the heart rate, the body starts to convert some of the excess weight to energy and sheds it.

But then again, I really do not have ny expertice in this, just adding my thoughts.